Brown sulfur dye and process of making same.



strain STATES PATENT FFICE.

TO KALLE & 00.,

OF SAME PLACE.

BROWN SULFUR DYE AND PROCESS OF MAKING SAME.

SPECIFICATION formingpart of Letters Patent No. 661,907, dated November 13, 1900.

Application filed September 25, 1900. Serial No. 31,095. (No specimens.)

To (tZZ whom, it may concern:

Be it known that we, KARL ELBEL, asubject of the King of Prussia, Emperor of Germany, and IGNAZ ROSENBERG, a subject of the Em- 5 peror of AustriaHung-ary, doctors of philosophy, residing at Biebrich-on-lhe-Rhine, Germany, assignors to KALLE & CO., of the same place, have invented certain new and useful Improvements in the Manufacture of a Brown I0 Cotton-Dye Containing Sulfur, of which the following is a specification.

Our invention relates to the manufacture of a new yellowish-brown substantive cotton- (lye by melting a condensation product of pyridiu and 1.3 dinitro 4 chlorobenzene with sodium sulfid and sulfur or with a caustic alkali and sulfur. The condensation product is obtained by heating 1.3 dinitro 4 chloro-- benzene with a molecularproportion of pyridin in presence of sodium carbonate or an excess of pyridin on the water-bath. The manner in which the condensation is carried out we describe by the following two examples:

Example 1. Twelve kilos of dinitrochlorobenzene are gradually added to a solution of six kilos of pure pyridin in three hundred and twenty liters of water, which is kept at 70 to 80 centigrade and which is strongly agitated. The mixture is then kept six hours at this temperature, always stirring well. After this time the dinitrochlorobenzene is totally absorbed and only a small quantity of a black resinous by-product remains undissolved. After filtration the clear solution is rendered strongly alkaline by addition of sodium carbonate and heated for about two hours to a temperature of 80 to 90 centigrade. After this time the formation of the condensation product and its separation in a 4 crystalline state, allowing easy filtration, is finished. After filtration the new product is pressed and dried.

Example2. Fortykilosofdinitrochlorobenzone are dissolved in eighty kilos of pyridin and heated on the water-bath while stirring well until the mixture has become almost solid by a separation of colorless crystals, which is the case after about an hour. After ooolingthe mass is stirred up with seven hun- 5o dred and fiftyliters of water. A small quantity of unchanged dinitrochlorobenzene and of a resinous by-product being removed by filtration, five hundred liters ofa ten-per-cent. soda solution are added to the filtrate. The fine brown precipitate obtained in this manner is transformed by about two hours heating on the water-bath into a crystalline state, allowing easy filtration. The new product is filtered, washed with cold water, pressed, and dried.

By both methods above described a small quantity of a second condensation product is formed. It remains in the last mother-liquor, from which it maybe precipitated by addition of common salt as a yellow crystalline precipitate which is easily soluble in water. The main product obtained when working according to example 1 or 2 is a red crystalline powder. Sometimes it represents crystalline leaflets with a bright steel-blue luster. It is insoluble in water, in acids, or alkalies, and in ether,benzene,chloroform,and other organic solvents. It may be recrystallized only from hot alcohol, acetone, or glacial acetic acid. It fuses at 172 to 173 centigrade under 5 simultaneous decomposition. The manufacture of the coloring-matter is carried out in the following manneri Example: Twenty-five kilos of the condensation product are stirred into a melted mixture of ninety kilos sodium sulfid and thirty kilos sulfur. The temperature of the meltis then raised to about to centigrade, always stirring well. When the melt begins to turn tough, it is spread on iron plates and 85 put into a stove previously heated to about The temperature is raised. within six hours up to The melt is then perfectly dry and friable and may directly be employed for dyeing cotton. 90

The new dyestuff is a dark-brown powder easily soluble in water with yellowish-brown color, less soluble in hot alcohol with greenishyellow color. The color of the aqueous solution turns darker on addition of caustic soda. 5 Hydrochloric acid causes a brown precipitate when added to the aqueous solution. Common salt precipitates the coloring-matter completely, even from dilute aqueous solutions. Concentrated sulfuric acid dissolves I00 the new dye with yellowish-brown color. In benzene it is insoluble.- The new product dyes cotton from a bath made up with salt and sodium sulfid yellowish-brown shades which are very fast to washing and to the action of light, acids, and alkalies. Byasubsequent treatment with sodium bichromate and acetic acid the shade is scarcely altered.

Now what we claim is 1. The manufacture of a new substantive yellowish-brown cotton dye by acting on 1.3

dinitr'o4chlorobenzene with pyridin and soda and by fusing the so-obtained condensation product together with sodium sulfid and sulfur substantially as described.

2. The new sulfur dyestuff easily soluble in water with yellowish-brown color, less so]- uble in alcohol with greenish-yellow color,

soluble in concentrated sulfuric acid with yellowish-brown color, which is precipitated din and soda, and by fusing the so-obtained condensation product with sodium sulfid and sulfur substantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

KARL ELBEL. IGNAZ ROSENBERG.

Witnesses:

JEAN GRUND, FRANZ HASSLACHER. 

